The present invention relates to a process for manufacturing self-adhesive multilayered label stock. More particularly, the self-adhesive multilayered label stock according to the present invention is a combination of a face paper with a release paper and printed with a main label message to be attached directly to goods or containers therefor and a face paper without a release paper and printed with a supplementary label message which is releasably placed on said face paper printed with the main message. The supplementary label message may be graphics or letters that are the same as those in the main message.
As one form of a prior art label to be attached to the surface of goods or the containers therefor, a self-adhesive label is well known. The prior art label stock includes a release paper and a face paper which is superimposed on the release paper and printed with label messages. The label stock may be punch-pressed together with the release paper into a given contour framing the label message, so that the user may peel off the punch-pressed frames of message and attach the same on the goods.
Further in the prior art, as disclosed in U.S. Pat. Nos. 1,896,834 and 4,323,608, there are known self-adhesive multilayered labels which, utilizing the advantages of said self-adhesive label and for the purpose of the advertizing function, include extra layers that are superimposed on the original label and carry description of the goods or a function like coupons. A typical construction of a self-adhesive label of this type includes a main label to be attached directly to goods, and supplementary label which is releasably pasted on the main label and printed as a coupon on its back and with the same graphics, etc. as the main label on its top face. A consumer may easily peel the supplementary label off the main label upon purchase and use the same as a coupon. As the main label is still attached on the goods, the consumer can tell the contents or confirm the manufacturer.
An essential challenge in preparing a self-adhesive multilayered label having the above construction is how the supplementary label carrying a label message of graphics, etc. which is similar to that on the main label should be superimposed on the main label while the main label is being printed with a label message. Supposing that the supplementary label is to be superimposed on the main label at the final stage of the production process, it is preferable that both the main and the supplementary labels are printed with label messages of graphics, etc. simultaneously at the same process step. However, since the label stock on which the main message is to be printed and the face paper on which the supplementary label message is to be printed are not the same but are separate sheets of paper. In order to print the label stock and the face paper simultaneously in one production system, it is necessary to provide two separate printers, making the size of system large and pushing up the production cost of the label.
In the prior art, due to the above reason, printing of the supplementary label message was not conducted at the step of printing graphic and other label message on the face paper of the label stock. Instead, it has been the practice to print on a sheet of plain paper supplementary label message which is similar to that of main label message before the step of printing the main label message. The plain paper printed with the supplementary label message is wound into a roll and stored until the time when it is supplied to the production line to be placed over the label stock carrying the main label message at a predetermined position. This inevitably necessitated the main and supplementary label messages to be printed separately. As the plain paper printed with the supplementary label message in advance is supplied at the time when the label stock is to be printed with the main label message, the entire production process needs long time to deteriorate efficiency.